Twitter is a social media platform that allows users to share short messages called tweets that are limited to 140 characters. On Twitter, users can choose other users to follow, and their tweets will appear in the follower's feed. A key difference between Twitter and other social networks is that relationships are asymmetric, with users having followers who see their tweets, and users they follow whose tweets they see. Twitter exposes users to different opinions and perspectives from around the world in a way that can broaden their knowledge and open their minds.